Telephone system



Jalll 6, 1942- K. J. CURLEY 2,269,335

TELEPHONE SYSTEM Filed May 13, 1941 BY. @M dwg,

ATTORN EY trouble lamps.

Patented Jan. 6, 1942 y 2,269,335 g j TELEPHONE SYSTEM Kieran Joseph Curley, IBrooiklym-N.y Y., assignor to American Telephone and Telegraph-Comy pany, a corporation of New York Application May 13, 1941, Serial No..393,156

` 3 claimsr (ci. 17a-175.23)

This invention relates to telephone systems of the automatic type and more particularly to improved arrangements for locating trouble or faults occurring in central oflce equipment of such systems.

In automatic telephone systems of the crossbar type a calling subscriber will be connected through one of a number of sender link controllers to one of a number of subscribers senders. The sender link controllers are so arranged that when trouble is encountered which stops the progress of the controller in selecting a sender, the controller will automaticaly time out and a trouble lamp will light in the proximity of the controller in trouble. The maintenance man will then place a hold plug in a jack individual to this controller and observe the action of certain relays in the controller circuit. If the trouble is in the controller circuit itself, it will repeat'on the sameframe and can usually be read other controllers to time out and operate their Under such conditions it'might be rather diiicult to utilize the present holdjacks .individual to each controller to quickly analyze and locate the trouble. In the arrangements of the invention the individual hold jacks are eliminated and a single key is provided, which, when operated in response to a trouble lamp will set certain arrangements in operation to allow a controller in trouble to time out and hold and to prevent other controllers from holding and thus allow the trouble to be readily located. Other objects and features of the invention will appear more fully from the detailed description thereof hereinafter given.

The invention may be more fully understood from the following description together with the accompanying drawing in the Figures 1 and 2 of which the invention is illustrated. Fig. 1 is a circuit diagram showing schematically a calling subscribers line connected to a district junctor and a subscriber sender. Fig. 2 is a circuit diagram illustrating in detail the arrangements of the invention.

In Fig. 1 is shown a telephone subscribers set I connected to a line link frame. The line link frame would have a multiplicity of telephone subscribers sets such as 2 connected to it also. The telephone subscribers set I would be connected to a line link control circuit 4, and thence would be connected to one of a number of sender link controllers such as 1 and 8. A connection 55 known in the art.

would be established to these controllers by means of thepaths 5 and 6. The function of a sending link controller, such as 1, would be to select one of a number of subscriber senders such as I I and I2. The selecting circuit is shown as 9. It would also be a function ofthe sender 'link controller, such as 1, to establish a connection through the sender link frame I4 to a dis- `trict junctor such as 20. One of the subscriber senders, such as Il, would then be connected las 1 or '8, to provide a holding jack at each of Vsuchl controllers.

Such holding jacks are shown in 'dotted lines as 24 and 25. If a connection were establishedbetween the controller 1 yand a 'subscribers set and trouble developed irl-the selecting operation of the controller, the controller would automatically time out and a trouble lamp (not shown) would light in the vicinityv of the controller. The maintenance man Would accordingly insert a hold plug in jack 24. As soon as the trouble was repeated the hold jack would cause the controller to hold with its equipment in the exact condition vobtaining when it encounteredy trouble in completing its function. Thus the maintenance man could readily locate andy clear the trouble. The details of such arrangements are not illustrated as they are well However the trouble might not occur in the controller 1 but might occur at a point outside the controller itself such for example as at a point 30. The apparatus at point 30 is common to other controllers. For example the controller 8 is connected to this point. After controller 1 timed out due to trouble at point 30, the subscribers set might be disconnected therefrom and connected to controller 8. Due to the fault at point 30 the controller 8 would now time out and cause its trouble lamp to operate. The maintenance man, who had rst placed a hold plug in the jack of controller 1, would now have to place a holdplug in the jack of controller 8. By this time the subscribers set might be connected to another controller connected to point 30 and the last-men- Vcluding relay lA1 times out.

tioned controller would time out. Thus the maintenance man might have to go from controller to controller to catch up with the trouble and might have considerable trouble in locat-` ing it.

The foregoing trouble is obviated by the arrangements of the invention. The individual jacks and hold plugs are not used by the maintenance man to hold the controller when it times out. Instead a single key or switch common to all of the controllers is provided. When a controller times out the key is operated and causes mechanism to condition all of the controllers so that the next time any one of the controllers times out it will hold but none of the `other controllers will hold even though they may subsequently -time out.

In Fig. 2 is shown a circuit diagram illustrating in detail the arrangements of the invention. As is well known in the art each sender link c'ontroller would be provided with a relay which would operate when the controller times out. These are illustrated as A1, Ag, A10 and A19. For

the ypurposes of this description only four such 'relays are shown. However one would be provided for each controller. As is valso well known in the art each sender link controller is also provided with another relay such as relays H1, H9, H10 and H19. These relays would be operated when a hold plug was inserted in the jack by the maintenance man in response to the operation of a trouble lamp. The function of these relays vwould be to cause the controller to hold after it again times out. As heretofore pointed out with the arrangements of the invention hold plugs and jacks individual to each sender link controller are no longer needed. Instead a-key K common to all of the sender link controllers is provided. When a controller times out and opcrates its trouble lamp the maintenance man operates the key K. This will close the following circuit; from ground, right hand contact of key K, conductor 32, over the contacts of all of the A series of .relays in all of the sender link controllers, conductor 33, left hand Contact of key.

K, conductor 34, Winding of relay 3|, to battery and ground. 'I'he completion of this circuit operates relay 3|. Relay 3| is a multi-contact relay, having a contact for each controller. The operation of relay 3| will connect ground to the windings of -all of the H series of relays :and operate them. This simulates the placing of hold plugs in all of the jacks o'f the controllers. The operation of the H relay of a controller conditions it to hold when it next times out. With the key K operated let us now assume that one of the controllers, such for example as the one in- As heretofore pointed out when the controller times out relay A1 will operate. This will break the previously traced circuit for relay 3| and release said relay. This will remove ground from all of the operating circuits of the H series relays and cause them to release except relay H1 because a holding circuit for relay H1 is provided as follows: from ground and battery, Winding of relay H1, conductor 35, make contact of relay A1, over the contacts of all the other A series relays, conductor 32, right hand contact of key K to ground. The timing out 'of the controller including relay A1 and the holding of relay H1 operated will in a well known manner cause that controller to hold. As the operating circuits of all the other H series relays have been opened and no holding circuits provided for 'these relays any other controller to ltime out Will'be prevented from holding. If desired a lamp L 'may be provided and operated by the operation of key K.

While the invention has been disclosed as embodied in certain specic arrangements which are deemed desirable, :it is understood that it is capable Vof embodiment in many and other widely varied iorms Without departing from the spirit of the invention as de'ned in the appended claims.

What is claimed is:

1l. In an automatic telephone system, central oice equipment comprising a plurality of sender link controllers, a key common to all of said controllers, and means operative when said key is operated'to prevent all of said controllers from holding except the rst one to time out subsequent 'to the operation of said key.

2. VInan automatic telephone system, central office equipment comprising a plurality of sender link controllers, each of said controllers including 'means 'for timing out and lmeans for holding after 'timing out, a key common to all of said controllers, means controlled by the operation of said key for conditioning all of said holding means 'for operation, and means operative when a controller next times out for unconditioning all of said holding means for operation except the holding means in said last mentioned controller.

A3. In an automatic telephone system, central oiiice equipment comprising a plurality of sender link controllers, e'ach of said controllers including a lrst relay operated when a controller times out, each oi said controllers including a second relay which when operated and when its controller has timed out will cause said controller to hold, a key common to all of said controllers, circuit arrangements controlled by the operation of said vkey for operating each of said second relays, and means responsive to the subsequent `operation of one of said first relays for closing a holding circuit for its associated second relay and for releasing all of said other second relays.

KIERAN J. CURLEY. 

